Various recent devices such as television sets and personal computers have a substrate on which electronic components such as semiconductor devices and capacitors are mounted using solder or the like. If any of the electronic components mounted on the substrate are defective, removing the defective electronic components from the substrate and mounting new replacement electronic components on the substrate, called repair work, are involved.
The repair work is desirably performed without damaging a component or components around a defective electronic component or without damaging the substrate on which the defective electronic component is mounted because the components other than the defective electronic component are continued to be used after the defective electronic component has been removed. Further, the repair work is desirably performed without damaging an electronic component body (such as a semiconductor chip) of the defective electronic component because failure analysis of the defective electronic component is performed after the defective electronic component has been removed.
In the related art, the repair work is performed by, for example, blowing hot air at a temperature equal to or higher than the melting point of solder by using an air heater onto an electronic component to be repaired to heat the electronic component and by melting solder. However, in this method, the electronic component is heated by blowing hot air onto the electronic component, which may hinder efficient heat transfer to solder. When the solder is melted, the temperature of the electronic component or the substrate becomes high, and the electronic component body or substrate, which is an important part for the electronic component to function, may be damaged. On a substrate with a high mounting density, it is difficult to blow hot air onto only the electronic component to be repaired, and hot air may also be blown onto a neighboring component or components, resulting in a possibility that the neighboring component or components will also be removed together with the electronic component to be repaired.
Many techniques for overcoming the above problems have been proposed. For example, a semiconductor device has been proposed in which a repair sheet having a heating wire is placed between a semiconductor package and a substrate so as to surround solder balls that connect the semiconductor package and the substrate. In this semiconductor device, only the semiconductor package can be removed by heating the repair sheet by using the heating wire to melt the solder balls surrounded by the repair sheet. In this semiconductor device, furthermore, only the semiconductor package can be mounted by mounting the semiconductor package on the substrate with the repair sheet being held therebetween so as to surround the solder balls and by heating the repair sheet by using the heating wire to melt the solder balls surrounded by the repair sheet (see, for example, Japanese Laid-open Patent Publication No. 11-87906).
Further, a ball-grid array (BGA) package substrate has been proposed on which a heat generating resistor layer such as a Ni—Cr layer is formed with an electric insulating layer disposed between the heat generating resistor layer and the BGA package substrate so as to surround lands on which solder balls are to be mounted. Only the BGA package can be removed from the substrate by causing a current to flow through the heat generating resistor layer to generate heat and by melting the solder balls that bond the BGA package to the substrate (see, for example, Japanese Laid-open Patent Publication No. 10-284820).
Further, a semiconductor device has been proposed in which a heat generating member of Ni—Cr or the like for heating projecting electrodes that connect a semiconductor chip and a substrate is provided in a certain portion on the semiconductor chip or the substrate. In this semiconductor device, only the semiconductor chip can be removed by heating the heat generating member to melt the projecting electrodes (see, for example, Japanese Laid-open Patent Publication No. 61-148830).
The techniques proposed in Japanese Laid-open Patent Publication No. 11-87906, Japanese Laid-open Patent Publication No. 10-284820, and Japanese Laid-open Patent Publication No. 61-148830, described above, may reduce damage to an electronic component body or a substrate, compared to a method of removing an electronic component by blowing hot air onto the electronic component by using an air heater. However, in the techniques proposed in Japanese Laid-open Patent Publication No. 11-87906, Japanese Laid-open Patent Publication No. 10-284820, and Japanese Laid-open Patent Publication No. 61-148830, transfer of heat to the electronic component body is not blocked, and there may still be a risk of damaging the electronic component body.